The conclusions from the article were:
> Creating the Flutter application only took approximately ⅓ of the time it took to create both native applications combined. This proves how much time you save by using cross-platform frameworks. Their Hot Reload functionality also sped up the development cycle a lot.
> I was able to create the Flutter app faster than the React Native app, but that’s because I had more experience with Flutter than with React Native. I also didn’t know how to manage state properly in the React Native. That’s why declare both Flutter and React Native the winners of this experiment.
For performance, Bram wrote:
> It’s obvious that the CPU-usage of the Flutter application is smaller than that of the React Native and Xamarin Forms applications, and that’s why I declare Flutter the winner of this experiment.
> In the second experiment it was concluded that the Flutter application was less taxing on the CPU than the React Native and Xamarin Forms applications. This doesn’t automatically prove that Flutter is more performant than React Native or Xamarin Forms.
> There are a lot of features that the Cocktailr app doesn’t have, like caching for example. That would reduce the amount of network requests that need to be made and would make the app more performant, meaning that it could lead to different results. I also only used CPU-usage as a performance indicator. I don’t have any data on the memory or battery consumption for example. These are also an important performance indicators.
We at Wanderlog (https://wanderlog.com) are using React Native largely because the ecosystem around it is a bit more mature than Flutter's at the moment. It's definitely saved us time vs. writing native code. We've definitely run into issues, and I think the main things we'd want to test as alternate performance indicators if we were choosing a framework again are:
1. How performant/easy-to-implement are long scrolling lists
2. How easy is it to animate the dimensions of Views that affect layouts of other views
3. How many libraries are there for things that will be dealt with native code? Dealing with the boundary with native code is always going to be tough